Ice making



R. D. BARTON June 25, 1957 ICE MAKING 2 Sheets-Sheet 1 Filed Sept. 15, 1954 June 25, 1957 R. D. BARTON ,7

ICE MAKING Filed Sept. 15, 1954 2 Sheets-Sheet 2 mg v 5 33 J4 (i die 67 VIII/I'll!'IIIlIIlIIIl/IIIIII w w x United States Pater ICE MAKING Ralph D. Barton, Evansville, Ind, assignor to Servel, Inc, New York, N. Y., a corporation of Deiaware Application September 15, 1954, Serial No. 456,110

1 Claim. (Cl. 62-7) This invention relates to automatic making, harvesting, drying and storing of ice pieces, generally called ice cubes.

This invention relates particularly to control means for energizing an ice ejecting mechanism responsive to the complete freezing of water in one of a plurality of iceforming compartments of an ice mold.

To provide a thermostat temperature setting closer to 32 F the freezing point of the water.

To provide an improved reset heater for the mold thermostat; and

To provide an improved means for assuring complete freezing of all water in a multi-compartment mold before ejecting ice pieces therefrom, without appreciably delaying the ejecting action.

Briefly, in accordance with this invention there is provided a multi-compartment ice mold formedas an aluminum die casting with all ice-forming compartments thereof bound by metal walls. The mold is placed in thermal contact with a freezing shelf to which is attached a refrigerating coil. The bottom of one of the ice-forming compartments, preferably the rear compartment, is thermally insulated from the freezing shelf,

' whereby the Water in this one compartment will be last In a patent application of Harry C. Shagalofi, Serial into a plurality of ice-forming compartments by a plurality of transverse partitions. The rear ice-forming compartment of the mold casting is open and is closed by a rear wall formed of plastic or other thermal insulating material. The ice mold rests on a freezing shelf that is cooled by a refrigerating coil attached thereto. The arrangement is such that, the rear wall of the rear iceforming compartment of the mold being formed of thermal insulating material, the water in the rear iceforming compartment is last to freeze; that is, the water in the other ice-forming compartments of the mold will be completely frozen while there is still some unfrozen water in the rear ice-forming compartment, which water is in conatct with the rear thermally insulated wall.

Still referring to the Shagalofi patent application, into this rear thermally insulated wall there is embedded a metal insert of good heat conductivity with the front surface of such insert in contact with water to be frozen in the rear ice-forming compartment of the mold, with an intermediate part of the insert in thermal contact with the sensing bulb of an electric thermostat and with the rear of the insert in thermal contact with a reset heater for resetting the mold thermostat after an ice ejecting cycle has been initiated. The metal insert, and, through it, the sensing bulb of the thermostat follow with some lag the temperature of the unfrozen water in the rear ice-forming compartment of the mold, so that, when the water in this compartment is completely frozen, which assures that the Water in the other iceforming compartments is already completely frozen, the sensing bulb of the mold thermostat will have reached a sufiiciently low temperature (20-25 F.) as to energize the thermostat and thereby initiate an ice ejecting cycle.

It is a general object of this invention to provide an improved control for automatic ice makers.

More specific objects of this invention are:

To provide a more accurate means of sensing the point at which ice is completely frozen in an automatic ice maker;

To provide a more direct means of sensing the point at which the ice is completely frozen;

to freeze, and the last water to freeze in this one compartment will be substantially at the top center thereof. The free end of a temperature sensing bulb of a mold thermostat is placed in physical contact with the last water to freeze at the top center of the rear ice-forming compartment. A reset heater for the mold thermostat is placed in thermal contact'with a portion of sensing bulb removed from the free end thereof, and when energized responsive to the complete freezing of the water in rear ice-forming compartment, the reset heater heats the bulb to reset the mold thermostat and to thaw the free end of the bulb free of the ice to which it has been frozen. An ejector mechanism that has meanwhile been energized by the mold thermostat ejects the ice pieces from the mold and brings them to rest in an up-side down position thereon for drying while a subsequent batch of ice is being frozen in the mold.

The invention, together with the above and other objects and advantages, is set forth in more technical detail in the following description and accompanying drawings, wherein:

Fig. 1 is a top plan, partly in horizontal section, of an automatic ice maker incorporating this invention;

Fig. 2 is a schematic wiring diagram for the controls of the ice maker;

Fig. 3 is a detail showing of a microswitch and cam operating mechanism therefor;

Fig. 4 is a transverse vertical section, taken on line 44 of Fig. 1, and showing the ice maker in the freezing compartment of a household refrigerator; and

Fig. 5 is a detail longitudinal vertical section through the rear of the ice mold.

GENERAL DESCRIPTION For purposes of illustration, this invention is incorporated in an automatic ice maker like that disclosed in a companion patent application of Carl J. Knerr, Serial No. 456,106, now Patent No. 2,717,497, filed concurrently herewith.

Referring to Fig. 4 of the drawings, the ice maker, indicated generally by reference numeral 10, is located within the upper or freezing compartment 12 of a household refrigerator. The ice maker is inserted through an opening in the rear wall of the refrigerator, which opening is closed by a closure member attached by screws to said rear wall (not shown). The freezing compartment 12 is cooled by a refrigerating coil 14 attached to the bottom wall thereof and forming an evaporator of a suitable refrigerating system, not shown. Resting on the bottom wall of the freezing compartment below and to the right of the ice maker, as viewed in Fig. 4, is an ice receptacle 16, adapted to receive and store ice pieces discharged from the ice maker. Only so much of the refrigerator as is necessary for a complete understanding of this invention is shown in the drawings. For a detailed description of the location of the ice maker and parts thereof in common with the instant invention, reference may be had to the above patent application of Carl J. Knerr.

Referring now to Figs. 1 and 4, the ice maker includes, generally, an ice mold 241, a mold heating element 30, a freezer shelf 32 upon which the mold is supported and which is cooled by a refrigerating coil 33, which coil is attached to the refrigerating system, not shown.* The ice mold is surrounded at the sides, front and bottom by thermal insulation and the insulation is encased in an insulation housing, to be referred to in detail hereinafter. Attached to the rear of the mold casting'is a combined support and housing member 40, which member is formed of plastic, such as phenol formaldehyde, or other. suitable thermal and electrical insulating material. An ejector mechanism 70 is mounted above the ice mold for rotary movement therethrough for sweeping the ice pieces therefrom, and is journalled" at its front end in a bearing at the upper front end of the mold and at its rear is the rearsupport and housing member 40. I

The rear housing member 40 is generally in the shape of a box, open at the rear and closed by a metal closure plate 41. The closure plate 41 supports three micro switches 140, 150 and 160, and provides bearing surfaces for a rear ejector shaft 76 and a timing gear shaft 86, to be referred to in detail. hereinafter. The micro switch 150 is located below the switch 140 (Fig. 1) and is shown separately in Fig. 3. Of the three micro switches: the micro switch 140 is operated by a cam 156 on the timing gear shaft and it deenergizes and reenergizes a compressor motor 180 (see wiring diagram, Fig. 2) of the refrigerator system at the beginning and end, respectively, of an ice release cycle; the micro switch 150 is' operated by the same cam 156 and this micro switch energizes a solenoid-operated water valve 100 (Fig. 1) for a precise number of seconds near the end of the ice release cycle; and the micro switch 160 is operated by a cam surface 156:: (Fig. 3) on the front of cam 156 and acts as a cut-off to automatically deenergize the ice maker when the ice receptacle 16 is filled with a given amount of ice pieces. The micro switch 160 is adapted for manual operation, as pointed out hereinafter.

Mounted on the rear of the metal closure plate 41 is a gear housing 83 (Fig. 1) which contains and journals an ejector gear 77, a timing gear assembly 85 and a motor gear 82. The timing gearl assembly is a form of Geneva movement, to be referred to in detailthereafter. An electric motor 80 for driving the ejector mechanism and the controls therefor is mounted on the rear of the gear housing'83. This electric motor is geared down from 3400 R. P. M. to approximately 2.5 R. P. M. at its output shaft, and is of a type that stalls while energized when the ejector blades initially contact the ice frozen solidly in the mold without burning out or oLherwise harming the motor. A motor of this type is disclosed and claimed in a copending patent application of Sven W. E. Andersson, Serial No. 325,145, filed December 10, 1952, now Patent No. 2,717,501.

Mounted on theright side of the ejector motor 80 (Fig. 1) is the precision solenoid-operated water valve 100. The inlet of valve 100 is connected to a suitable source of water under pressure, such as the house line, and the outlet is connected by a conduit to the rear of a vertical passage 42 formed in the rear support member 40, which passage discharges water through an outlet 42a (Fig. 4) into the rear ice-forming compartment of the mold. A mold thermostat 122 (Fig; 5) and a reset heater 130 for transferring heat to the sensing element 124 of the mold thermostat to reset such thermostat, each to be referred to in detail hereinafter, are mounted on the rear of the ice maker.

Ice r nold Referring now to Figs. 1 and 4, the ice mold 20 com- Casting and provided with a washer.

prises an aluminum die casting divided into a plurality of ice-forming compartments 21 by transverse partitions 22. The ice-forming compartments are generally semi circular in transverse vertical section, and the partitions are tapered horizontally from the right to the left side thereof as viewed from the front in Fig. 1. The partitions have a slight taper in the vertical direction, as pointed out in the above Knerr patent application. The partitions are each provided with an upstanding projection 23 on the right side and with a weir or notch 24 in the left side thereof, as viewed in Fig. 1. A thermal insulator 25, made of nylon or the like, is fitted upon each of the upstanding projections 23 of the mold partitions. As shown in Fig. 4, and as pointed out hereinafter, the insulators 25 support one side of the ice pieces during the drying thereof and prevent the ice from sticking to the upstanding projections of the mold partitions. The outer surface of each of the weirs 24 is of the same general curvature as the inner surface of the ice mold compartments, and the inner surface of the weirs is substantially vertical. As viewed in Fig. 1, the weirs are progressively smaller from the rear to the front of the mold.

Referring to Fig. 4, the ice mold is provided with an upstanding and oflset flange 26 along the left side thereof, which flange is clamped in heat exchange relation with the left side wall of the freezing compartment 12 by a clamp 27 secured by a plurality of screws 27a. The front and rear walls 28 and 29, respectively, each of which is an integral part of the mold casting, slant outward from right to left as viewed from the front in Fig. 1. The mold heater 30, in the form of a hairpin coil, is located in slots 31 (Fig. 4) in the bottom ofthe mold at each side thereof. 'The mold that rests on the freezer shelf 32 that is cooled by the refrigerating coil 33 also is in the form of a hairpin. As shown in Fig. 4, the refrigerating coil 33 is formed out of round for good thermal contact with the undersurface of the freezer shelf to which it is welded, or otherwise secured. The refrigerating coil '33 is connected to a suitable refrigerating machine, not shown.

As shown in Fig. 4, the mold is provided with a boss 34 projecting from the bottom rear thereof which passes through an opening in the freezer shelf 32, and which clamps the rear of the mold to the shelf by means of a thimble 35 held in place by a screw 36 threaded into the boss. The front of the mold is attached to the freezer shelf bya screw (not shown) threaded into the mold The front of the mold is shaped as shown in Fig. 1, and is provided with an integral boss drilled to receive a bearing 38 made of nylon or other suitable thermal insulating material, and the bearing is provided with a filler (not shown) made of neoprene rubber, or like material. The bearing 38 receives and supports the front end of the ejector shaft 71, to be referred to hereinafter.

As shown in Fig. 1, the front ice-forming compartment of the mold is formed with an overflow duct 39 that in,-

sures against excess filling of the ice-forming compartments, as pointed out hereinafter. In case of overflow, the duct 39 discharges into the ice receptacle 16 located beneath and to the right of the mold (Fig. 4).

Ice mold insulation compartments and transferred therefrom through the mold andthe freezer plate 32 to the coil, and to add to the decorative appearance of. the ice maker, the mold is provided with insulation and with decorative housing members at the sides, front and bottom thereof. The insulation members are made of unicellular sponge rubber "that is impervious to moisture and, as shown in Figs. 1

and 4,include a right side member 51, a left side member 52, a front member (not shown) and a bottom member .54; The side and front insulation members are formed to fit the exterior contour of the ice mold, and the bottom insulation member is cut-out to receive the refrigerating coil 33, the screws for attaching the ice mold to the freezer shelf and a set of s:rews 64 for attaching this bottom insulation housing to the freezer shelf.

The insulation housing members, which are preferably made of a thermal insulating, moisture-proof and decorative material, such as white polystyrene, include a right side member 55, a bottom member 56 (Fig. 4) and a front member 57 (Fig. 1). The right side member (Fig. 4) is formed with an inwardly and upwardly projecting flange 58 adapted to fit within a groove 59 along the upper right side of the ice mold and with a lower inwardly extending flange provided with a groove 60 to receive the right upper edge of the bottom housing member 56. The bottom housing member 56 is dish-shaped, open at the back, and includes spacing ribs 61, which provide a space between this member and the bottom insulation member 54, and two openings, only one of which is shown at 62 for access to the screws by which the mold is attached to the shelf. This bottom housing member is attached to the freezer shelf by four screws 64, located at the front and back at each side thereof. Also, the bottom housing member 56 is provided with a channel (not shown) at the front left corner thereof (Fig. 1) to receive the lower end of the overflow duct 39 of the ice mold. The front insulation housing 57 is shaped as shown in Fig. 1 and is attached by a screw (not shown) to a bracket 67, which bracket is attached to the front upper portion of the ice mold by a pair of screws 68. The front closure member 57 is formed with access openings at the top and front thereof, and the front opening is closed by a decorative, spring-held disk (not shown). Any moisture that may migrate into the mold insulation during freezing periods is collected in the bottom housing member and drains therefrom through the openings therein into the ice receptacle 16 during the ice thawing periods, as pointed out hereinafter.

Ejector mechanism As shown in Figs. 1 and 4, the ejector mechanism 70 includes a front ejector shaft 71 mounted for clockwise rotation at its front end in the nylon bearing 38 at the front of the ice mold and at its rear end in a suitable bearing located in the rear housing member 40, which member, as pointed out heretofore, is made of thermal insulating material. Extending tangentially (Fig. 4) from one side of the front ejector shaft 71, and formed integral therewith, is a plurality of ejector blades 72; there being one such blade for each ice-forming compartment 21 of the ice mold 20. The ejector shaft 71 is mounted in the plane of the longitudinal axis of the ice mold, and is spaced from the upper edges of the mold partitions 22. At the rear, this ejector shaft is connected by thermal insulating coupling 74 (Fig. 1) to a rear ejector shaft 76, which rear ejector shaft is connected to the ejector motor 80 by a timing gear assembly 85, to be described in detail hereinafter. As shown in Fig. 4, the outer upper edges of the ejector blades 72 cooperate with the insulators 25 in supporting the ice pieces above the ice mold for drying wetted surfaces thereof before discharge into the storage receptacle 16.

Power and timing mechanism As pointed out heretofore, the electric motor 80 for driving the ejector mechanism 70 and the controls therefor is a stall motor equipped with internal gears (not shown) for reducing its speed from 3400 R. P. M. to approximately 2.5 R. P. M. at its output shaft 81. The motor field winding 80a and overload limit switch 80b are shown diagrammatically in Fig. 2. The motor output shaft 81 (Fig. 1) is formed with a square portion 81a upon which is keyed a gear 82. The motor gear 82 is meshed with a rear gear 87 of the timing gear assembly 85, which timing gear assembly is fixedly mounted on a shaft 86, which shaft is journalled at its rear in a bearing 86a formed in the gear housing 83 and at its front in a bearing (not shown) formed in the metal closure plate 41. In front of the gear 87 (as viewed in Fig. 1) is a timing gear 88 having a toothed portion 88a and a blank portion 88b on the periphery thereof. In front of the timing gear 88 is a timing cam 90 having a high portion and a low portion (not shown) on the periphery thereof. The gears 87 and 88 and the cam 90 are held as an assembly by dowel pins. shaft 76, and in mesh with the teeth of timing gear 88, is an ejector gear 77, and in front of the ejector gear (Fig. 1) and fixed to the rear ejector shaft 76 is an ejector cam 78 having a high portion and a low portion (not shown) on the periphery thereof.

The arrangement is such that upon rotation of the ejector motor 80, the motor gear 82 (Fig. 1) rotates the rear gear 87 of the timing gear assembly, which two gears have meshing teeth throughout the 360 of their periphery, and rotation of the gear 87 causes rotation of the timing gear 88 and of the timing cam 90. As the timing gear 88 is rotated, the toothed portion 88a thereof is brought into mesh with the teeth of the ejector gear 77, which latter gear is provided with teeth throughout the 360 of its periphery, whereupon the ejector gear 77, the rear ejector shaft 76, the ejector cam 78 and the front ejector shaft 71 are rotated in unison. Rotation of the ejector gear 77 continues (neglecting for the present the stalling of the ejector mechanism by contact of the ejector blades 72 with the ice frozen solidly in the mold compartments) until the blank portion 88b of the timing gear 88 is juxtaposed with the teeth of the ejector gear at which time the high portion of the timing cam 90 is in mesh with the low portion of the ejector cam 78, whereupon the ejector gear 77 and shafts 76 and 71 are held stationary while the ejector motor 80, the motor gear 82, and the timing gear assembly and cam continue to rotate for a definite period before the motor is deenergized, as pointed out hereinafter. During a freezing cycle of operation, the timing gear 88 and the ejector gear 77 are substantially in the relative positions shown in Fig. 1 with the high portion of cam 90 in contacts with the low portion of cam 78. Thus the ejector mechanism is locked in the position shown in Fig. 4 for drying the ice pieces resting thereon.

Water metering and mold filling mechanism Mounted on a bracket 101 on the side of the motor 80 is the solenoid-operated water valve (Fig. 1). This valve is a precision mechanism in that it accurately meters a definite quantity of water therethrough when open; the opening and closing of which is accurately timed as pointed out hereinafter. This valve includes a body member 102 having an inlet connection 103 and an outlet connection 104. The inlet connection is provided with a nipple 103a that extends through the rear of the refrigerator (not shown) for connection to a suitable source of water under pressure, such as the house line. The outlet connection 104 is connected to the ice mold by a tube 105 that opens into the passage 42 formed in the rear housing member 40. For a detailed description of the solenoid-operated valve 100 reference may be had to the above copending patent application of Carl J. Knerr, Serial No. 456,108, filed September 15, 1954, now Patent No. 2,717,504.

Controls In accordance with this invention and as shown in Fig. 5, the rear wall 29 of the ice mold is formed as an integral part of the mold casting and the rear housing member 40 is attached by suitable screws (not shown) to the rear of the mold casting. So as to partially insulate the rear ice-forming compartment of the mold from the freezing shelf 32 and thereby make sure that the water in this rear compartment is last to freeze, the bottom of the mold directly beneath the rear ice-forming compartment is formed with a recess or undercut extending trans- Fixedly mounted on the rear ejector 7 versely of the mold and into which is placed a piece of thermal insulating material 32a. As in the above pending patent application of Harry QC. Shagaloif, Serial No. 325,097, filed December 10, 1952, the complete freezing of the water in the rear ice-forming compartment of the mold is utilized to energize the ice release mechanism. In the instant disclosure, the water freezes substantially in the manner shown in Fig. 5, which shows a freezing stage near the end of a freezing cycle, with unfrozen water in contact with the tip of the sensing bulb in the rear ice-forming compartment, while in the other compartments the freezing is almost complete.

In accordance with this invention, to provide a more accurate means of sensing the point at which the ice is completely frozen in rear ice-forming compartment, a sensing bulb 124 of the mold thermostat 122 is formed .as shown in Fig. and mounted in a manner that the 'tip or free end 124a thereof projects into the rear iceforming compartment slightly below the level of water to be frozen therein. The sensing bulb 124 is inserted through an opening 40a in the rear housing member 40. The sensing element includes a cylindrical portion 124b on which the reset heater 130 is mounted. The reset heater 130 includes a sleeve or spool 131 mounted in good thermal contact on the cylindrical portion 124!) of the sensing bulb, and having two separate resistance elements 132 and 133 wrapped around the circumference thereof. For certain installations, as pointed out hereinafter, the resistance element 133 may be omitted. The spool 131 is formed of a heat conducting, electrical insulating material. The combined reset heater and thermostat sensing bulb are encased in a cup-shaped housing 134, formed with lugs 135 on opposite sides thereof and attached to the rear housing member 40 by a pair of screws 136. The housing 134 is preferably formed of phenol formaldehyde or other suitable thermal and electrical insulating material.

The resistance element 132 of the reset heater is, for example, a 2.0 watt heater that is placed in series with the mold heater 30 (Fig. 2) and is, therefore, energized at the beginning of an ice release cycle, as described hereinafter. When energized, the heater 132 furnishes sufiicient heat to the cylinder portion 124k and from there to the tip" 124a of the sensing bulb to thaw the tip free of the ice (Fig. 5) in which it has been frozen and to rest the thermostat switch 122a to the closed position (Fig. 2).

In order to prevent response of the mold thermostat from some point of lower temperature than that ofthe tip 124a contacting the water in the rear ice-forming compartment of the mold, the resistance element 133 which is, for example, a 0.3 watt heater, is connected in series with the compressor motor 180 (Fig. 2) and is energized during ice freezing cycles. When energized, the element 133 supplies a'small amount of heat to the cylindrical position 12% and to the capillary tube 123 of the mold thermostat to: maintain their temperature above the thermostat setting (2628 F.). The resistance element 133 may, be

' eliminated in installations where it is assured that the temperature of the capillary tube 123 will never fall below that of the thermostat setting.

The tip 124a of the sensing bulb is located under the ejector shaft 71, to the right of center of such shaft (Fig.

4) and fixed in suitable position so that during an ice release cycle, the ice in the rear ice forming compartment of the mold is rotated away from the bulb tip by the rear ejector blade 72a. To allow rotation of the ejector blade -72a past the 'tip'124a of the sensing bulb, a slot 721) (Fig. 5) is formed in the blade. For clanity of illustrapatent application of Carl J Knerr, referred to above, the

micro switc'h140 that deenergizes and .reenergizes the compressor motor 180 (shown only in the wiring diagram 8 in Fig. 2) at the beginning and end, respectively, of an ice release cycle, is mounted by a pair of screws 142 on the metal closure plate 41. This micro switch 140 is separated from the closure plate 41 by a strip of insulation 143. This micro switch includes a spring-pressed plunger 141 that is urged into contact with a cam 156, to be described in detail hereinafter, and when in contact with the high portion of the cam, which is the stationary position thereof during an ice freezing cycle, the switch is in the full line position shown in Fig. 2 and the compre-ssor motor 180 is energized; whereas shortlyafter the beginning of an ice release cycle, the high portion of the cam 156 leaves the plunger 141, and the switch 140 is shifted to the broken line position (Fig. 2), whereupon the compressor motor is deenergized, and remains so until near the end of an ice ejecting cycle when the high portion of the cam 1'56 again contacts the switch plunger 141 and returns the switch 140 to the full line position.

The second micro switch 150 that energizes and deenergizes the solenoid valve 100, is also mounted on the closure plate 41 by a pair of screws 152 (Fig. 3). This switch 150 includes a plunger 151 operated by a lever 153. The lever 153 is pivoted near its lower end on a post 154, and at its upper or free end is bifurcated to receive a roller 155. The roller rides upon the cam 156 and is urged into contact therewith by a compres sion spring 157. The cam 156 (as best shown in Figs. 1 and 3) comprises a front portion 156a fixedly mounted on the timing gear shaft 86 and a rear portion 156b adjustably mounted by a set screw (not shown) upon the shaft 86. The purpose of this adjustment is to vary the combined length of the high or camming surfaces of the front and rear portions of the cam; the combined length of-which high portions of the cam determine the length of time that the solenoid valve is energized and water flows therethrough to the ice mold. It is to be noted that the plungers 141 and 151 of micro switches and 150, respectively, are operated by the same cam 156, and during an ice freezing cycle the switches 140 and are in full line positions (Fig. 2) with the compressor motor energized and the solenoid valve deenergized.

p The micro switch 160, that automatically deenergizes the ice maker when the ice receptacle 16 is filled with a given amount of ice pieces, is mounted on a bracket 162 (Fig. l), the lower end of which is attached by a screw (not shown) to themetal closure plate 41, and the upper end of which is adjustably connected to the closure plate by a screw 164 having a compression spring 165 thereon. The micro switch 160 includes a springpressed plunger 161 operated by a cam 166 mounted on a shaft 167, which shaft is journalled at its ends in partition walls 43 and 44 of the rear housing member 40. The purpose of the adjusting screw 164 is to center the plunger 161 below the cam 166 (Fig. l). A lift arm 170, including a sleeve 171 with a roller (not shown) attached thereto by a shoulder screw (not shown), is fixedly and adjustably mounted on the shaft 167, near the partition wall 43. A second sleeve 174 is attached to the opposite end of the shaft 167 and a stop-arm 175, made of stainless steel or other relatively rigid material, is attached at one end to sleeve 174. The stop-arm is formed with an off-set near its attached end (as shown in Fig. l) and is provided with a relatively heavy metal ball 176 on its free end. The lift arm is rotated by a cam member 156c formed on the front surface of the cam 156 (Fig. 3).

The arrangement is such that upon rotation of the timing gear assembly 85 the high portion of the cam 1560 is brought into contact with the roller (not shown) on the arm 170, whereupon the shaft 167 is rotated in a clockwise direction through a given are. This clockwise rotation of the shaft 167 brings the high portion of cam 166 into contact with the switch plunger 161, which depresses the plunger and opens the switch160 (Fig. 2),

thereby opening a circuit to the ejector motor 80 in which this switch is contained. Clockwise rotation of the shaft 167 also lifts the stop-arm 175 and attached ball 176. Continued rotation of the timing gear assembly 85 (Fig. 1) causes the high portion of cam 1560 to leave the roller on the lift-arm 170, whereupon, assuming that the ice storage, receptacle 16 is not yet filled with ice pieces, the ball 176 falls by gravity and through the arm 175 rotates the shaft 167 counterclockwise to its normal position which removes the high portion of cam 166- from the switch plunger 161, and this in turn causes the switch 160 to return to its closed position (Fig. 2). Should the ice receptacle 16 be filled with the desired amount of ice pieces, gravity movement of the ball 176 and stop-arm 175 is blocked by the ice, causing the switch 160 to remain open after the high portion of cam 1560 has left the lift-arm 170 and until some ice has been removed from the receptacle.

As in the companion application of Carl J. Knerr, referred to above, the ice maker may be shut down at will and caused to stand idle by manually lifting the ball 176 and stop-arm 175 to an uppermost position and engaging the arm in a spring clip 179 (Fig. 4) mounted on the ceiling of the freezing compartment 12 directly above the stop-arm 175. With the stop-arm 175 engaged in the spring clip, the ice maker will complete a freezing cycle, but, because the switch blade 160a of micro switch 160 is held in open position (Fig. 2) against a dead terminal 160e,. a subsequent ice ejecting cycle cannot be initiated. Therefore, the ice maker stands idle with a batch of ice pieces frozen in the mold and a second batch of ice resting on the ejector mechanism above the mold (Fig. 4). ready to be discharged into the storage receptacle. Operation of the ice maker may be resumed by manually removing the stop-arm 175 from engagement with the spring clip 179.

a 115 volt A. C. supply circuit, between. which are connected by several circuits, the compressor motor 180 for the refrigeration system, the micro switches 140, 150

and 160, the electric thermostat 122 for the ice mold, the. ejector motor 80 with they motor field 80a and limit switch 30b, the mold heater 30, the resistance elements 132 and 133 of the reset heater and the solenoid Water valve 100. The full line position. of the several switches in Fig. 2 is their normal position during an ice freezing cycle. of the ice maker.

A first circuit (the only circuit for the compressor motor 180) includes the conductor T2, a movable switch blade 1400611 full line position) of micro switch 140, a stationary contact 140b, a conductor 200, the resistance element 133, a thermostat switch 190a of the thermostat 190 for the refrigerating system, the compressor motor 180, and T1. The sensing bulb 19012 of thermostat 190 is placed in thermal contact with the refrigerating coil 14 for the freezing compartment 12 (Fig. 4.) As pointed out in the above companion patent application of Carl J. Knerr, with certain installations it may be desirable to continue operation ofthe compressor motor during ice release cycles of the ice maker, in which case, the conductor 200 is-connected directly to T2 and the switch 140a is utilized only to establish and discontinue holding circuits, as pointed out hereinafter.

A second circuit (a first circuit for the ejector motor .80) includes the conductor T2, a conductor 20 1, mov- '(in broken line position) of the ice mold thermostat 122, a conductor 203, a. stationary contact 1400, a conductor 204, a stationary. contact 150b, a movable switch 10 blade 150a (in full line position) of micro switch150, a conductor 205, the motor field 8.0a, the motor limit switch b, a conductor 206, a conductor 207 and T1.

A third circuit (second circuit for the ejector motor 80) includes the conductor T2, movable switch blade 140a (in broken line position) of micro switch 140, the stationary contact 1400, conductor 204, stationary contact 150b, movable switch blade 150a (in full line position), conductor 205, motor field 80a, motor limit switch 80b, conductor 206, conductor 207 and T1.

A fourth circuit (third circuit for the ejector motor 80) includes the conductor T2, movable switch blade 140a (in broken line position), the conductor 203, movable switch blade 1224 (in full line position), a stationary contact 1220, a conductor 208, conductor 205, motor field 80a, motor limit switch 80b, conductor 206, conductor 207 and T1.

A fifth circuit (a circuit for the mold heater 30 and the resistance element 132 of reset heater is in parallel with each of the above circuits for the ejector motor 80 between the micro switch 150 and T1) includes a conductor 209, the mold heater 30, a conductor 210, the resistance element 132, a conductor 211, conductor 207 and T1. This circuit to the mold heater and reset heater is energized when switch blade 160a is in full line position, switch blade 122a is in broken line position and switch blade 150a is in full line position, and when switch blade a is in broken line position and switch blade a is in full line position, and when switch blade 140a is in broken line position and switch blade 122a is in full line position. Thus, the mold heater 30 and the resistance element 132 of reset heater 130 are energized at all times that the ejectormotor 80 is energized.

A sixth circuit (the circuit for the solenoid water valve 100 is in parallel with that part of the circuits for the ejector motor 80 between the micro switch 150 and the motor limit switch 80b) includes the movable switch blade 150a (in broken line position), a stationary contact 150e, a conductor 212, the coil ofthe solenoid 100, a conductor 21 3, the limit switch 80b of the ejector motor 80, conductors 206, 207 and T1. This circuit forthe solenoid water valve is energized only when the movable switch blade 140a is in broken line position, the movable switch blade 122a is in full line position, the movable switch blade 150a is in the broken hne position and the motor limit switch 805) is closed. The movable switch blade 150a is in the broken line position only near the end of an ice release cycle when the high portions of cams 156a and 1561) (Fig. 3') are brought into contact with the roller or" micro switch 150.

OPERATION In operation, assuming that the several switches are in the full line position shown in Fig. 2, that the ice receptacle 16 (Fig. 4) is not yet filled withthe desired quantity of ice pieces and that the stop arm is in the position in Fig. 4; in other words, the ice maker is in operation.

'With the several switches. in the full line position (Fig. 2),

the compressor motor is. energized and water is being frozenin the several compartments of the ice mold. Due to the fact that the thermal insulation strip 32a (Fig. 5) separates the bottom of the rear ice-forming compartment of the mold from the freezing shelf 32, water in the rear ice-forming compartment will be last to freeze, and when this water is completely frozen, the temperature (28-30 F.) at which the thermostat is set will have been reached at the tip 124a of the sensing bulb, whereuponv the thermostat switch 122a. is shifted from the full to the broken line position (Fig. 2).

This shifting of the thermostat switch 122a establishes an initial circuit from T2 through conductor 201, stop arm switch 160:: (in full line position), stationary terminal 160b, conductor 202, stationary terminal 122b, thermostatic switch blade 122a (in broken line position), con- -ductor 2.03, stationarycontact 140e, conductor 204, stationary'conductor 150b, switch blade 150a (in 'full line position), conductor 205, motor field 80a, motor.limit switch 80b, conductor 206, conductor 207 and T1, whereupon the ejector motor 80 is energized. The shifting of the thermostat switch 122a to the broken line position also establishes a paralleled circuit through the conductor 209, the mold heater 30, conductor 210, resistance element 132 of the reset heater, conductor 211, conductor 207 and T1, whereupon the mold heater 30 and the resistance element 132 are. energized and begin to thaw the ice free of the mold compartments and the tip 124a of the sensing element free of the ice at the top center of the rear compartment.

Energization of the ejector motor 80 causes rotation of the motor, motor gear 82, timing gear 87, gear shaft 86, timing gear 88, timing cam 90, and cam 156. The ejector motor 80 is otherwise unloaded during its initial rotation, and shortly after the cam 156 begins to rotate, the high portion of'cams 156a and 156b leave the plunger 141 (Fig.- 1)" of micro switch 140, whereupon the movable switch blade 140a is shifted from the full to the broken line positionin Fig. 2. This shifting of the switch blade 140a deenergizes the heating'element 133 and the comamen compartments of the mold, whereupon the ejector'motor is stalled. However, the ejector motor 80, the mold heater 30 and the reset heater element 132 remain energized, with the motor urging the ejector fingers against the ice, the mold heater'thawing the ice free of the mold compartments and the heating element 132 thawing the tip 124a of the sensing bulb free of the ice into which it is frozen, so that the instant'the ice is thawed free of the mold compartments, the motor .80 resumes its rotation and the blade 122a to the full line position shown in Fig. 2, the

pressor motor 180 of the refrigerating system and establishes a holding circuit from T2 to T1 through the switch blade 140:: (in broken line position), stationary contact 1400, conductor 204, stationary contact 150b, movable switch blade 150a (in full line position), conductor 205, ejector motor 80, and conductors 206 and 207. This shifting of the switch blade 140a also establishes a holding circuit through the mold heater 30 and the reset heater 132.- With continued rotation of the ejector motor and the timing gear assembly, the cam surface 1560 on the front of cam 156 is brought in contact with the roller of the stop arm assembly 170, whereupon the shaft 167 is rotated clockwise (Fig. l) with the result that the plunger 161 of micro switch 160 is depressed and the switch blade 160a is shifted from the full to the broken line position (Fig. 2). Rotation of the shaft 167 also lifts stop arm 175 and attachedball 176 to an upper position (not shown).

At about this point in the rotation of the ejector motor and of the timing gear assembly, the high portion of cam 90 will have been removed from the low portion of cam '78, and the toothed portion 88a of gear 88 will have meshed with the teeth of the ejector gear 77, whereupon the ejector gear 77, rear ejector shaft 76, ejector cam 78, coupling member 74 and the front ejector shaft 71 with fingers 72 attached thereto are rotated in a clockwise direction (Fig. 4). This clockwise rotation of the ejector shaft 71 and attached fingers 72 causes the dried ice pieces that have been resting on the ejector fingers 72 and on the insulators (Fig. 4) to be discharged over the side of the mold into the ice receptacle 16.

Shortly after the batch of ice pieces have been discharged over the side of the mold, the timing mechanism will have rotated to the point that the high portion of cam surface 156a will have passed the roller on stop arm assembly 170, whereupon the weighted ball 176 on stop arm 175 will fall by gravity (assuming that the ice receptacle 16 is not yet filled with ice pieces) and rotate the shaft 167 counterclockwise (Fig. 1) thereby removing the high portionof cam 166 from switch plunger 161 and returning switch blade 160a to the full line position (Fig. 2). Should the ice receptacle 16 be filled with the desired quality of ice, at this point, the weighted ball 176 will be held up by the ice and the stop switch 160a will be held in the broken line or open position (Fig. 2). However, because of the holdingcircuit through switch blade 140a (in broken line position) the ejecting cycle will continue to completion, but a new ejecting cycle cannot be initiated until some ice pieces are removed from the storage receptacle 16 and thestop switch 160a closed.

The ejector motor continues to rotate until the ejector fingers 72 contact the ice frozen solidly in the several high portion of cam 166 on shaft 167 will have drawn away from the switch plunger 161 and the switch blade 160a will have returned to its full line position (Fig. 2), assuming that the ice receptacle 16 is not yet filled with ice.

By the time that the ejector motor has rotated the ejector shaft 71 and attached ejector blades 72 to the position shown in Fig. 4, the toothed portion 88a of timing gear 88 (Fig. 1) will have left the teeth of ejector gear 77, and the high portion of timing cam 90 will be in contact with the low portionof the ejector cam 78, whereupon the motor is againunloaded although it continues to rotate. During this unloaded period of rotation of the ejector motor, the high portion of cams 158a and 15% contact the roller 155 on switch arm 153, whereupon the plunger 151 of micro switch 150 (Fig. 3) is depressed and the switch blade 150a (Fig. 2) is shifted to the broken line position, thereby energizing the coil of the solenoid water valve 100.

The high portions of cams 158a and 158b hold the switch plunger depressed and the solenoid energized for approximately ten seconds during which time water in a metered quantity flows through the solenoid valve 100, the outlet tube (Fig. 1), vertical passage 42 and outlet passage 42a (Fig. 4) into the rear ice forming compartment of the mold. From the rear ice forming compartment, the water flows through the notches 24 in the mold partitions to the forward compartments of the mold. The ejector motor 80 and the timing gear assembly continues to rotate unloaded, whereupon the high portions of cams 156a and 156b withdraw from the roller 155 of switch arm 153, thereby shifting the switch 150a back to the full line position which deenergizes and closes the solenoid valve 100. Shortly thereafter, the high portions of cams 156a and 156b will have returned to the'positions shown in Fig. 1 with the plunger 141 of micro switch depressed and the switch blade 140a shifted back to the full line position in Fig. 2. This ends the ejecting cycle and starts the next freezing cycle with the several switches again in their full line position. 7

It is to be noted that, with the switch blade, a in the broken line position (Fig. 2), the only circuit to the coil of the solenoid water valve 100 is from T2 through the switch blade 140a (in broken line position), stationary contact 140c, conductor 203, switch blade 122a (in full line position), stationary contact 1220, conductor 208, switch blade 150a (in broken line position), stationary contact 150e, conductor 212, coil 100, conductor 213, limit switch80b, of the ejector motor, conductor 206, and conductor 207 to T1. Also, with the switch blade 150a in broken line position, the only circuit to the ejector motor 80, the mold heater 30 and the resistance element 132 of the reset heater is through conductor 208;

' the mold heater, the reset heater and solenoid water valve deenergized, and with the water valve closed. Inability of the reset heater to reset the thermostat switch 122a is an indication that the thermostat has failed, lost its charge, and must be replaced before the ice maker can be rendered operative.

Also, it is to be noted that the coil of the solenoid water valve 100 is wired in series with the overload limit switch 801) of the ejector motor, so that, should the switch 80b open for any reason and stop the ejector motor while the high portion of cams 156a and 156b are in contact with the roller 155 of micro switch 150, thereby holding the switch blade 150a in the broken line position (Fig. 2) with the solenoid coil energized and the water valve open, the coil is immediately deenergized and the valve closed.

Without further description it is thought that the novel features and advantages of the invention will be readily apparent to those skilled in the art to which this invention appertains, and it will, of course, be understood that changes in form, proportions and minor details of construction may be resorted to without departing from the spirit of the invention and scope of the claim.

What is claimed is:

In an automatic ice maker, an ice mold, means for dividing the mold into a plurality of ice forming compartments, means for filling the mold with water to be frozen,

refrigerating means for freezing the water in the mold, means for freeing the ice from the mold, means for removing the ice from the mold and control mechanism for said filling, freezing, freeing and removing means, said ice mold having one compartment thereof at least partially insulated from the refrigerating means whereby the water is completely frozen in the other of the plurality of compartments while there is still unfrozen water in said one compartment, and said control mechanism including a thermostat having a temperature sensing element thereof in physical contact with the last water to been in said one compartment.

References Cited in the file of this patent UNITED STATES PATENTS 2,181,582 Gerber Nov. 28, 1939 2,221,694 Potter Nov. 12, 1940 2,241,624 Smellie May 13, 1941 2,419,376 Shaw Apr. 22, 1947 2,429,851 Swann Oct. 28, 1947 2,643,524 Wilbushewich June 30, 1953 2,682,155 Ayres June 29, 1954 

